Image correction method, imaging device, and inspection device

Abstract

An image correction method for correcting multiple original images captured under illumination by multiple different light source colors in generating a composite image by superposing the original images, includes obtaining a correction amount for correcting a position of a fiducial mark recognized from a reference image of a specific light source color in reference images of the multiple different light source colors; obtaining correction amounts for correcting positions of the fiducial mark recognized from the reference images of other light source colors than a specific light source color to the reference position in the reference image of the specific light source color; and when the original images are captured, correcting collectively distortion aberration and chromatic aberration of the original images of the multiple different light source colors using the correction amounts associated with the multiple different light source colors.

The invention claimed is: 
     
       1. An image correction method for correcting multiple original images captured under illumination by multiple different light source colors in generating a composite image by superposing the original images, the image correction method comprising:
 (a) a step of obtaining a correction amount for correcting a position of a fiducial mark recognized from a reference image of a specific light source color in reference images of the multiple different light source colors resulting from imaging a member on which the fiducial mark is provided under illumination by the multiple different light source colors to a reference position of the fiducial mark in the reference image of the specific light source color and setting the correction amount by associating the correction amount with the specific light source color; 
 (b) obtaining correction amounts for correcting positions of the fiducial mark recognized from the reference images of other light source colors than the specific light source color to the reference position in the reference image of the specific light source color for the other light source colors and setting the correction amounts by associating the correction amounts with the other light source colors; and 
 (c) when the original images are captured, correcting collectively distortion aberration and chromatic aberration of the original images of the multiple different light source colors using the correction amounts associated with the multiple different light source colors. 
 
     
     
       2. The image correction method according to  claim 1 ,
 wherein in the step (a), the center position of the member and the position of the fiducial mark in the reference image of the specific light source color are recognized, an inclination of the member is derived based on the center position and the position of the fiducial mark, and the reference position in the reference image of the specific light source color is determined using the inclination of the member so derived and an ideal position of the fiducial mark to thereby obtain the correction amount, and 
 wherein in the step (b), the position of the fiducial mark is recognized for each of the reference images of the other light source colors to thereby obtain the correction amount. 
 
     
     
       3. An imaging device comprising:
 a storage section configured to store the correction amounts set using the image correction method according to  claim 1  while associating the correction amounts with individual light source colors; 
 a light source section configured to irradiate multiple different light source colors; 
 an imaging section configured to capture original images making up a composite image under illumination by the multiple different light source colors; and 
 a correction section configured to correct collectively distortion aberration and chromatic aberration of the original images of the individual light source colors using the correction amounts associated with the individual light source colors. 
 
     
     
       4. An inspection device comprising:
 a storage section configured to store the correction amounts set using the image correction method according to  claim 1  while associating the correction amounts with individual light source colors; 
 a light source section configured to irradiate multiple different light source colors; 
 an imaging section configured to image a board on which components are mounted as original images under illumination by the individual light source colors; 
 a correction section configured to, when the original images are captured, correct collectively distortion aberration and chromatic aberration of the original images of the individual light source colors using the correction amounts associated with the individual light source colors; and 
 an inspection section configured to generate a composite image by superposing the original images whose distortion aberration and chromatic aberration are corrected to thereby execute a mounting inspection of the components based on the composite image so generated.